when i first got the game (discovered it on an indie blog) i got stuck at the embark screen because being on a laptop if hav different +/- keys than a PC keyboard. It took me a good five minutes to consider plugging in a pc keyboard. I nearly gave up on the game at this point (abit dim with hindsight).
I didnt find learning the game to difficult having already played nethack, and having had to learn to use software like Arc GIS. The main things that shook me were.
Building a well, it didnt occur to me that I the player would have to channel water to under neath the well and actually dig the well. I just assumed i got the stuff and the rest was automated like a typical rts game.
It took me a while to get the hang of assigning tasks to dwarfs. Theres a job manager and other screens (i dont use these now, ever). i tried to use them to get the dorfs to do stuff rather than pressing D or Q and initiating tasks at the workshop or resource.
I found the wiki very helpful, i used the 1st year fortress tutorial alot.
I think the issue was the initial shock of the complexity level. In most strategy or management games most of the activity is automated for you. You build a farm and it produces resource by its self for the rest of the game (or its life). in df you build a farm on the right surface type, under ground (or above ground), plant seeds in the right seasons, make sure theres a farmer and gatherers, store em, cook em etc. This complexity isnt a problem but it would be better if the rules or way the game works was communicated very early in the game